Which embryonic stage consists of a solid, compact mass of sixteen or more cells?
A - The morula
B - The blastocyst
C - The blastula
D - The ICM
Answer: A - The morula
The MORULA comes after the zygote has divided several times, and is an embryonic stage consisting of a solid, compact mass of 16 or more cells. When it reaches the 64 cell stage, the internal and external cells become separate lineages.